If it's Isaac then why not just have him playable in all Golden Sun games?

To me the only game he was playable the way he should be was Broken Seal, sure he was playable in Lost Age, but Feelix had to be the leader, which imo Isaac should have took over following the Jupiter Lighthouse event.

In Dark Dawn he wasn't playable at all, and at the beginning the game would troll you with him in the party, but he just sat there and did nothing as if Matthew and Karis were the only characters there.

When I saw the topic title, I was like "Oh, this should be interesting," but when I read "Who is the Link of Golden Sun?" I honestly lost interest.

Gee I wonder why, maybe I should of said Mario because allow me to answer that question, Isaac is the Mario of the Golden Sun series, Felix is like the Luigi of the series.

I always felt maybe the Proxians like the Koopas Mario and Luigi battle, but like Bowser sometimes in Mario games, I feel we could see a good Proxian, much like how we saw Bowser help Mario on some occasions, especially considering we have a new enemy with the mysterious High Emperor, in whom is still at large and we have no clue who he is.

Alex is kind of like the Wario of Golden Sun, remains Anti-Hero the entire time, although to me he's more of a cross between Wario and Magus from Chrono Trigger.

If Jenna is like Peach due to Daisy and then if Sheba is matched with Felix, that probably makes her the Daisy of the series, then Mia is like the Rosalina.